US1917113A

US1917113A - Superregenerative receiver

Info

Publication number: US1917113A
Application number: US607992A
Authority: US
Inventors: Clarence A Gunther
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1932-04-28
Filing date: 1932-04-28
Publication date: 1933-07-04
Anticipated expiration: 1950-07-04
Also published as: DE675518C

Description

y 1933- t c. A. GUNTHER 1,917,113

SUPERREGENERATIVE RECEIVER Filed April 28, 1932 A +A +3 osc.

Inventor: C l arence AG unther',

His Attorney 16 is composed of an iron-cored inductor 17 having a tuning capacitor 18 in parallel therewith. A radio frequency choke 19 is connected in the grid circuit between the grid element of the oscillator discharge device 20 and the inductor 17. The anode circuit of the electron discharge device 20 is provided with an inductor 21 whichis arranged in an inductive relation to the inductor 17 to permit the circuit to oscillate. The electron discharge device 20 of the oscillator circuit 16 is connected across the input circuit of the electron discharge detector 6 by means of a capacitor 22 arranged between the grid element of the oscillator discharge device 20 and the grid condenser 4 of the electron dis charge detector 6, and the connection between the cathodes of the electron discharge devices 6 and 20. The impedance coupling member or capacitor 22 is of such value in comparison with the, capacitor 18 of the oscillator circuit that the desired frequency of the oscillations in the oscillator 16 is not disturbed. The radio frequency choke 19 is of a value presenting a high impedance to the ultrahigh frequency energy present in the input circuit of the detector 6 but also presenting a low impedance to the frequency generated by the oscillations of the oscillator discharge device 20.

A variable resistor 23 is connected in the common return of the cathodes of

discharge devices

6, 13 and 20 to provide a means for controlling the temperature of the cathodes. In the output circuit of the detector 6, I have arranged a filter 25 for reducing undesired frquencies such as those which comprise the background noise. This filter, while not essential to the operation of the super-regenerative detector. is a desirable feature, and is composed of an inductor 26. a resistor 27, a second resistor 28 and. an iron-cored inductor 29 in series with the primary winding 30 of an output device 31. A plurality of

capacitors

32, 33 and 34-. are connected respectively between the

elements

26 and 27, 28 and 29, 29 and 30 and the common return connection 35 whichis connected to the cathodes of the electron

diseh arge devices

6, 13 and 20. A capac: itor 36 in series with an iron-cored inductor 37 is connected between the common return connection 35 and a point between the resistors 27' and 28. A capacitor 38 is connected between the return conductor 35 and the conductor 39 which is connected to one terminal of the primary winding 30 of the output device 31. A variable resistor 40 is arranged between a suitable source of potential' for the anode of detector 6 and the conductor 39 for the purpose of providing a control of the potential applied to the anode of the detector 6. The secondary Winding 41 of the output device 31 be connected toan audio frequency amplifier or a suitable translating device.

means of the resistor 40 so that normally sustained oscillations are present in themput circuit of the detector 6 and the audible frequency introduced by the oscillator 16 is present in the output only when a carrier wave is being received. lVith this ad ustment, an audio frequency will be present in the output only at the time when continuous wave signals are being received.

The super-regenerative action is introduced into the. detector 6 by'meansof, the action of the

electron discharge devices

13 and 20 operating in accordance with the frequencies generated by the

oscillators

9 and 16. The incoming ultra high frequency signals which are of the continuous wave variety are modulated by the audible frequency generated by the oscillator 16 to provide a signal in the output circuit of the detector having a constant audio frequency, regardless of the frequency of theincoming signals or any variation therein. The signals produced in the output circuit of the de tector 6 remain at a constant frequency regardless of any variations of the detector circuit variables as long as the frequency of the oscillator 16 is not altered.

It has been found that a certain relation erative action resulting inoptimum opera-v tion. For ultrahigh frequency reception, the audio frequency suppliedby a source such as the oscillator 16 would be too loW for proper super-regenerative action. To supply the proper frequency for such optimum operation, the oscillator 9 is provided in addition to the oscillator 16 ,Whiehprovides the necessary audio frequency component for the modulation of the signals. To obtain this desideratum in the operation of the receiver, the oscillator 9:is tuned so that the effect produced by the combined action of the two

electron discharge devices

13 and 20 is such that the greatest sensitivity is obtained. The combined use of the

electron discharge devices

13 and 20 results ina greater gain, greater ease in tuning and less critical adjustment of the component parts of the apparatus than would'be the case if the proper frequency were not obtained.

' In operation, the electron discharge devices13 and 20 operate to periodically suppress the normally-sustained oscillations present in the input circuit of the detector 6, thereby varying the degree of regeneration present. These

electron discharge devices

13 and 20 are enabled to perform this funclation generators for preventing the high frequency signal energy in said detector in put circuit from. entering said oscillation generators and for causing said oscillation generator discharge devices periodically to suppress said normally-sustained oscillations thereby to produce simultaneously a super-regenerative detector action and modudetector action, and means connected to said.

grid element and included in said oscillation generator circuit to cause said grid element periodically to draw current having a steep wave front form, said means also serving to isolate said oscillation generator elements from said regenerative detector circuit.

5. In a high frequency radio receiving system, the combination of an electron discharge detector arranged in a circuit to produce normally-sustained oscillations in said circuit at the signal frequency, means for collecting high "frequency signal energy and for impressing said energy upon said detector circuit, an electron discharge device including a grid element and a cathode arranged in a circuit to generate high frequency oscillations, means for coupling said grid element and said cathode to said detector circuit, whereby said electron discharge device periodically suppresses said normally-sustained oscillation to produce a super-regenerative' detector action, and means connected to said grid element and included in said oscillation generator circuit to maintain at all times a high external impedance between said-element and said cathode, said means also serving to prevent high frequency signal energy from entering the oscillation generator cir-' cuit. i V

6. A regenerative receiving circuit having an input circuit, said regenerative receiving circuit being arrangedto produce normallysustained'oscillations, a plurality of electron discharge devices arranged in oscillatory circuits, each of said discharge devices having a grid element and a cathode, means for maintaining the external grid-to-cathode circuit impedance of said discharge devices high at all times and for causing the internal grid-